How do you know if your alternator is going out if it's still charging your battery?
Feb 18, 2016 at 9:02 AM
CATAFINA
✓Experienced Mechanic
167 POSTS
Read the battery voltage before you start the car then read it again while engine is running it should read within 2 volts if not there's a problem.
For example its 12.5 before you start the car and it reads 14.5 while running-the alternator is doing its job
Feb 18, 2016 at 10:25 AM
CJ MEDEVAC
✓Experienced Mechanic
11,000 POSTS
CATAFINA IS SPEAKING "ELECTRICALLY"
IF IT'S SQUEALING OR MAKING A GRINDING SOUND, "MECHANICALLY", THE BEARINGS OR BUSHINGS INSIDE MAY BE WORN OUT OR FAILING.
THE MEDIC
Feb 18, 2016 at 11:18 AM
STRAILER
✓Experienced Mechanic
55,512 POSTS
Also if a diode is going out the alternator will change the battery with AC voltage which is bad, here is more information on how to test it correctly.